The soldering of a connector to a glass surface in the automotive vehicle using solder-to-glass connectors in various vehicle applications has been known for some time. Common applications of solder-to-glass connectors include the connection of a power source to an electrically conductive substrate such as an ink that is placed and dried on the vehicle glass by any of several known methods. Typical vehicle applications include rear window defrosters and radio antennae. Other applications are known. In general, today's modern vehicle requires between two and four solder-to-glass connections.
Solder-to-glass connectors have traditionally used leaded solder to make a rigid connection. However, current and developing environmental regulations restrict the use of lead in most applications, including in solder. Without lead, the solder connection is not as durable as with lead.
Alternatives to the use of lead in solder have been attempted. For example, a common alternative is indium. While providing some of the strength characteristics of lead, commercially available lead-free solder formulations with indium exhibit low temperature melting points which can compromise the integrity of the joint at high temperatures.
Accordingly, as in so many areas of automobile technology, there is room for improvement in the area of solder-to-glass connectors.